___________ Capacitance is present in pn junction diode.a)Diffusion capacitanceb)fixed cpacitancec)Transition capacitanced)depletion capacitancee)Variable capacitance

In a pn junction diode, both (c) Transition capacitance and (d) Depletion capacitance are present.

Here's why:

1. Transition Capacitance: This is also known as junction capacitance. It is present in the pn junction diode due to the charge storage in the depletion region. When the diode is reverse biased, the width of the depletion region increases. This causes an increase in the stored charge, which in turn increases the junction capacitance.

2. Depletion Capacitance: This is the capacitance due to the depletion region of the pn junction diode. When the diode is forward biased, the width of the depletion region decreases. This causes a decrease in the stored charge, which in turn decreases the depletion capacitance.

So, both transition and depletion capacitance are present in a pn junction diode, and they change based on whether the diode is forward or reverse biased.

In a pn junction diode, both Transition (or Junction) capacitance and Diffusion capacitance are present.

1. Transition (or Junction) Capacitance (c): This type of capacitance is present due to the variation in the depletion layer width with the applied bias voltage. When the diode is reverse biased, the width of the depletion region increases, which decreases the junction capacitance.

2. Diffusion Capacitance (Cd): This type of capacitance is present due to the variation of charge storage in the junction with the applied forward bias voltage. When the diode is forward biased, the charge storage increases, which increases the diffusion capacitance.

So, the correct answers are a) Diffusion capacitance and c) Transition capacitance.